On the crescent-shaped pond in the southeast corner of Central Park, a spectacularly colorful duck floats on the surface with an air of majesty.

His head looks like a punk rocker’s multicolored mohawk. Beneath his beady black eyes, fringed orange feathers splay across his dark purple chest. His bill is colored a striking hot pink and sits under an emerald green forehead.

The male Mandarin duck, native to East Asia, should not be in the middle of Manhattan. And yet, against all odds, he is here. And he is dazzling.

On Oct. 10, the duck was first spotted near the Pond in Central Park and a video was shared on social media. The city’s avid birders were amazed: These ducks are commonly found in China and Japan — not the United States. Plus, ducks aren’t allowed to be kept as pets in the city.

David Barrett, the creator and manager of Manhattan Bird Alert, a Twitter account used to document bird sightings across the borough, originally believed there were three ways the duck may have reached Central Park.

First, he could have escaped from a local zoo. Second, he could have fled captivity somewhere nearby, such as New Jersey. Or third, a duck owner could have tired of having a feathered friend and dumped him in the park.

Shortly after he was spotted, the duck disappeared. “For almost two weeks we didn’t know what happened to it,” Mr. Barrett said. “We assumed it got eaten by a raptor.”

But on Thursday, the duck was spotted by the boat basin at West 79th Street, Mr. Barrett said. And on Sunday, he reappeared in the Pond, floating not too far away from the concrete jungle at 59th Street and Fifth Avenue. He had the same band on his right leg as the duck that was seen earlier.

One possible origin story was ruled out. The duck did not come from any of New York’s four major zoos run by the Wildlife Conservation Society, said Craig Piper, the director of city zoos for the organization.

On Tuesday afternoon, Mr. Barrett, 54, returned to the Pond to check on the Mandarin duck. Carrying binoculars, Mr. Barrett, who works as an investor and computer scientist when he’s not birding, circled the shore trying to spot the glamorous creature.

After many minutes of fruitless searching, he spotted the duck nestled near a rock across the Pond, on the eastern shore of the Hallett Nature Sanctuary.

Joined by a fellow birder on a lunch break from her day job, Mr. Barrett began to strategize how he’d coax the duck from the other side, which was thick with trees and shadows in the late afternoon. “We need to be enterprising,” he said.

First, the pair of birders tried to entice him. Mr. Barrett purchased a salted soft pretzel from a cart in the park, ripping off tiny pieces and tossing them off the shore. No luck.

The second birder, Sandra Critelli, muttered that she needed to get back to the office soon. “But that damn duck!” she said.

As his next option, Mr. Barrett tried to chase the duck away from its nook on the distant side of the Pond. After walking around the Pond to the forested nature sanctuary, Mr. Barrett climbed around trees and over branches to reach the shore. Then, he began to quack.

Yes, quack. And soon, a small group of ducks began to swim out of the shadows.

Mr. Barrett sprinted over the bridge and back to the other side of the Pond. By the time he got there, the Mandarin duck was already basking in the sun with his mallard friends, posing for awe-struck onlookers with cameras.

Swimming near the shore of the Pond, New York’s Mandarin duck, with his orange upturned wings and black-white rump, was the center of attention.

“He’s the star of the show,” said Juan Jimenez, a 74-year-old photographer who has been taking pictures in Central Park for decades.

“As far as the colors are concerned, only nature can provide that,” Mr. Jimenez said. “We could try to paint it, but you won’t be able to.”

As of Tuesday, park officials had no intention of capturing the duck, said John McCoy, the deputy director of the Urban Park Rangers, which is part of the city’s Department of Parks and Recreation. He added that they still do not know for certain whether the duck arrived on his own or was left there by a fed-up duck owner.

Park officials will take action only if the duck gets injured and needs medical care, Mr. McCoy said. But the duck, which has no known name, appears to be quite healthy, paddling across the sprawling Pond and even integrating with the native mallards.

Mr. Barrett has faith that the Mandarin duck can survive in his current habitat. Because this type of duck is a “dabbler,” which means it often feeds by moving its bill across the water to find insects and vegetation, it could last in Central Park for a while, he said.

“As long as it has open water, it will do just fine,” Mr. Barrett said. “He might live very happily on the Central Park Pond.”